<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Moving On</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="GTK+ 2.0 Tutorial"
HREF="book1.html"><LINK
REL="PREVIOUS"
TITLE="Stepping Through Hello World"
HREF="x281.html"><LINK
REL="NEXT"
TITLE="More on Signal Handlers"
HREF="x335.html"></HEAD
><BODY
CLASS="CHAPTER"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>GTK+ 2.0 Tutorial</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="x281.html"
ACCESSKEY="P"
>&#60;&#60;&#60; Previous</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="x335.html"
ACCESSKEY="N"
>Next &#62;&#62;&#62;</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="CHAPTER"
><H1
><A
NAME="CH-MOVINGON"
></A
>Moving On</H1
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="SEC-DATATYPES"
>Data Types</A
></H1
><P
>There are a few things you probably noticed in the previous examples
that need explaining. The gint, gchar, etc. that you see are typedefs
to int and char, respectively, that are part of the GLib system. This
is done to get around that nasty dependency on the size of simple data
types when doing calculations.</P
><P
>A good example is "gint32" which will be typedef'd to a 32 bit integer
for any given platform, whether it be the 64 bit alpha, or the 32 bit
i386. The typedefs are very straightforward and intuitive. They are
all defined in <TT
CLASS="FILENAME"
>glib/glib.h</TT
> (which gets included from 
<TT
CLASS="FILENAME"
>gtk.h</TT
>).</P
><P
>You'll also notice GTK's ability to use GtkWidget when the function
calls for a GtkObject. GTK is an object oriented design, and a widget
is an object.</P
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="x281.html"
ACCESSKEY="P"
>&#60;&#60;&#60; Previous</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="book1.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="x335.html"
ACCESSKEY="N"
>Next &#62;&#62;&#62;</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Stepping Through Hello World</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
>&nbsp;</TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>More on Signal Handlers</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>